The United States yesterday accused Iran of firing on an MQ-1 Predator drone operating in international airspace over the Persian Gulf last week.

Pentagon spokesman George Little told reporters the unmanned aerial vehicle was on a routine but classified surveillance mission about 16 miles off the Iranian coast Nov. 1 when it was fired on at least twice by an Iranian Su-25.

The unarmed Predator was not hit by the gunfire and later landed safely at a base in the region, Little said, declining to identify the base. The drone never breached the 12 nautical-mile limit that would be within Iranian territory, Little said.

“Based on our assessment it was not hit. It did not receive any damage,” Little said, later adding: “Our working assumption is that they fired to take it down. You’ll have to ask the Iranians why they engaged in this action.”

The Pentagon believes the incident marked the first time a U.S. drone has been fired upon while flying in international airspace over the Persian Gulf, Little said.  The United States has lodged a protest with the Iranian government through the Swiss, he said. Washington and Tehran do not have formal diplomatic relations.

The United States has a wide range of diplomatic and military options to protect assets and forces in the region. “I am not going to speculate on what we may or may not do,” he said. U.S. forces did not immediately respond to the Iranian assault on the UAV, he said.  

“We have communicated to the Iranians that we will continue to conduct surveillance flights over international waters and over the Arabian (Persian) Gulf consistent with longstanding policy,” Little said.

After the intercept, the Predator flew further away from Iranian airspace, was tailed for some time before being allowed to proceed on its own, Little said. He did not say how long the encounter lasted.

“Once it came under fire … it moved further out, and the Iranian aircraft continued to pursue MQ-1 for some period of time before letting it return to base,” he said. He did not say which service was operating the drone.

Earlier this year, another UAV came down in Iranian territory. Tehran claimed to have commandeered the UAV while Washington attributed the crash to a malfunction.